What type of set is A = {x ∈ Z : x² = 2}?
Answer and explanation
Correct answer: Empty and finite
There is no integer whose square is 2. The integers nearest to a possible square root are 1 and 2, but 1² = 1 and 2² = 4; in fact, √2 is irrational and is not an integer. Therefore no integer satisfies the defining condition, so A = ∅. The empty set has cardinality zero and is finite.
Frequently asked questions
What is the correct answer to this question?
Empty and finite
Why is this the correct answer?
There is no integer whose square is 2. The integers nearest to a possible square root are 1 and 2, but 1² = 1 and 2² = 4; in fact, √2 is irrational and is not an integer. Therefore no integer satisfies the defining condition, so A = ∅. The empty set has cardinality zero and is finite.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.